Dressed in a black tuxedo and his signature cowboy hat, McGraw took the stage alone, beginning the song a cappella before a band and chorus of backing vocalists joined him. He remained the only one on stage, however. Antique lamp posts surrounded him, giving off a glow of rich gold.

Remembering Glen Campbell With Pictures Through the Years

The song appears in the documentary film Glen Campbell: I’ll Be Me, which chronicled the music icon's final tour as he struggled withe the progression of his Alzheimer's. The emotional lyrics look back on Campbell’s life and also reflects on everything his progressing Alzheimer’s is slowly taking from him from an almost unbearably resolute perspective, reflecting, "And best of all, I'm not gonna miss you."

Written by Campbell and Julian Raymond, the track was also nominated for Best Original Song this year. Sadly, the singer could not be on hand to witness the tribute; Campbell has been living in an assisted care facility for most of the last year, and his wife, Kim, has stated that he will never perform in public again. The song is from the final recording session of his legendary career, and McGraw calls it “a powerful song from one of the true legends of the music industry.”

A recent article revealed that Campbell is too sick to understand if his song wins at the Oscars this year, and in fact no longer even remembers that he was once a top-selling recording artist.

McGraw approached the song cautiously, not deviating far from Campbell's recorded version. From a bar stool he sat belting out the simple melody, and when he was done, many of the celebs in the audience were seen wiping away tears.

"I'm Not Gonna Miss You" also took home Best Country Song honors at the 2015 Grammy Awards earlier this month. This isn't Campbell's first Academy nomination. In 1969 his song "True Grit" was nominated from the film of the same name.